Electrode configuration for vibrating beam transducers
First Claim
1. A transducer comprising a substantially solid piezoelectric beam having a natural resonant frequency and a longitudinal axis that extends between two opposed clamped ends;
- and a plurality of electrodes mounted by the beam for causing the beam to vibrate by producing forces directed along the longitudinal axis, at least one of the electrodes defining means for increasing the tendency of the beam to vibrate in a predetermined flexure mode at the natural resonant frequency, to the exclusion of harmonic frequencies, said means comprising a configuration of said at least one electrode that varies as a function of longitudinal position along the beam such that when a voltage difference is applied between the electrodes, the longitudinal force produced by the electrodes as a function of longitudinal position, approximates a longitudinal strain versus longitudinal position profile of the predetermined flexure mode at the natural resonant frequency.
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Accused Products
Abstract
A technique is described for tailoring the configuration of electrodes on a piezoelectric beam such that the tendency of the beam to vibrate in a predetermined flexure mode is enhanced. The mode has a predetermined longitudinal strain versus longitudinal position profile. At least two electrodes are mounted on the beam, and the configuration of at least one electrode varies as a function of longitudinal position, such that when a voltage difference is applied between the electrodes, the longitudinal force produced by the electrodes, as a function of longitudinal position, approximates the longitudinal strain versus longitudinal position profile. The configuration may be varied by varying the width of the electrode or the position of the electrode on the underlying beam surface.
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Citations
11 Claims
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1. A transducer comprising a substantially solid piezoelectric beam having a natural resonant frequency and a longitudinal axis that extends between two opposed clamped ends;
- and a plurality of electrodes mounted by the beam for causing the beam to vibrate by producing forces directed along the longitudinal axis, at least one of the electrodes defining means for increasing the tendency of the beam to vibrate in a predetermined flexure mode at the natural resonant frequency, to the exclusion of harmonic frequencies, said means comprising a configuration of said at least one electrode that varies as a function of longitudinal position along the beam such that when a voltage difference is applied between the electrodes, the longitudinal force produced by the electrodes as a function of longitudinal position, approximates a longitudinal strain versus longitudinal position profile of the predetermined flexure mode at the natural resonant frequency.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
Specification